The basketball team at Brooklyn’s Prospect Heights HS is flunkin’ instead of dunkin’.

Prospect had to drop its heralded boys varsity basketball program this year after six of its 11 players “failed out” in December, making them academically ineligible.

The Prospect Heights Cardinals – which four years ago made the Public School Athletic League championship playoffs and has sent numerous star players to college programs – is forfeiting all its games after Dec. 13 because it doesn’t have enough eligible players left to field a team.

“After the players failed off, we understood there was no way the team could continue. It was very disappointing to everybody,” said the school’s athletic director, Tarek Ali.

“Five students did what they were supposed to do to be able to play, and now they don’t have a chance.”

The players learned a hard lesson about the game of life.

“I was surprised. I thought we could keep on playing,” said a dejected, 16-year-old Jamaal Joseph, a 6-foot-2 power forward who transferred from a school in Maryland and is one of the passing students.

Joseph said the elimination of the season hit home recently when coach Floyd Lane, a retired professor from City College, collected the red-and-white uniforms from players.

But Joseph said the players who failed out have only themselves to blame.

“The players should have kept their grades up. They know they’re on the team. They should be responsible for keeping the team together,” Joseph said during an interview outside the Crown Heights school.

Another player, forward Arnold Nembhard, admitted he was disappointed when his grades went south in the second marking period – and he was cut from the team.

“I love basketball,” Nembhard said.

Lane said he was heartbroken and might not return next season.

“I had no indication this was going to happen,” he said. “It was disheartening. It was a tough blow to take after being there for nine years.

“We made the playoffs four years ago and things were going well, but things slowly declined. This year, players were coming to school, but they weren’t attending classes.”

He said the school set up tutoring sessions for the struggling players – to no avail. He admitted he warned students about cutting classes and “just walking the halls.”

And there were no backup or reserve players to draw from to keep the team alive.

“Prospect Heights has a sizable number of kids who are of varsity-caliber and ineligible,” Lane said. “I’m very much concerned with their future.

“I’ll help every bit that I can to get the team back for next year, but I’m not sure if I want to go back.”

Prospect Heights’ academic woes extend beyond its basketball team. Nearly half of the 312 students enrolled as freshmen in 1997 never made it to their senior year in 2001, state Education Department figures show.